Body Plans

?
What is morphogenesis?
The regulation of an organism's anatomical development
1 of 18
Why are drosophila a popular choice for genetic research?
They are easy to keep, they have short life cycles and they are small
2 of 18
What are homeobox genes?
Genes that contain a homeobox and are responsible for the development of body plans
3 of 18
What is a homeobox?
A section of DNA (180 base pairs long) coding for a 60 amino acid long protein called a homeodomain
4 of 18
What is a homeodomain?
A protein that binds to DNA and switches other genes on and off (transcriptional regulator)
5 of 18
What is the Pax6 gene thought to be involved in and why?
The development of eyes, as it was found mutations in this gene would cause blindness in humans, it was also shown to cause the same effects in drosophila, and mice
6 of 18
What are hox genes, where are hox genes found and how does this effect how they are expressed?
Hox genes are a group of homeobox genes found in animals, they are found in gene clusters on the chromosomes and the order in which the genes appear along the chromosome is the order in which they are expressed
7 of 18
What are diploblastic and triploblastic organisms?
Di- 2 primary tissue layers, tri- 3 primary tissue layers
8 of 18
Radial symmetry
Seen in diploblastic organisms, eg jellyfish, they have no left or right sides, just top and bottom
9 of 18
Bilateral symmetry
Seen in most animals, organisms have both left and right sides and a head and tail instead of a top and bottom
10 of 18
Asymmetry
Where an organism has no lines of symmetry eg sponges
11 of 18
Name 2 cell processes essential in shaping organisms
Mitosis (cell division and proliferation) and apoptosis (programmed cell death)
12 of 18
How does mitosis effect the shaping of an organism?
Increases number of cells, resulting in growth
13 of 18
How does apoptosis effect the shaping of an organism?
Apoptosis if programmed cell death and so it is involved in things like forming the fingers, sculpting the individual fingers
14 of 18
Describe the stages of apoptosis
1) The cell gets the signal to start apoptosis, 2) the nucleus starts to condense, cell shrinkage and blebs form, 3) Nucleus fragments and blebs pinch off into vesicles called apoptotic bodies, 4) phagocyte engulfs apoptotic bodies
15 of 18
Name an external factor that effects the expression of regulatory genes
Temperature change, effecting the homeostatic balance
16 of 18
Name an internal factor affecting the expression of regulatory genes
Changes due to hormones or psychological stress
17 of 18
Drugs can also effect gene expression, give an example of how drugs have affected gene expression
Thalidomide was given to pregnant women to treat morning sickness, however it prevented the normal expression of a particular hox gene, causing the babies to have shortened limbs. This effect is now been exploited to stop the development of tumours.
18 of 18

Other cards in this set

Card 2

Front

Why are drosophila a popular choice for genetic research?

Back

They are easy to keep, they have short life cycles and they are small

Card 3

Front

What are homeobox genes?

Back

Preview of the front of card 3

Card 4

Front

What is a homeobox?

Back

Preview of the front of card 4

Card 5

Front

What is a homeodomain?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all DNA, genetics and evolution resources »